Anticipatory nausea and vomiting is a significant adverse reaction encountered by child and adolescent cancer patients receiving chemotherapy treatments. Since treatment-related side effects have been linked to medical noncompliance and treatment refusal in this population, pharmacologic and behavioral treatments have been investigated to control these side effects. Pharmacological treatment of anticipatory nausea and vomitting has not proved very potent. Behavioral interventions are fairly successful in reducing side effects but have yet to be tested in a group design study with children and adolescents. This project will investigate the comparative effectiveness of two behavioral interventions in reducing anticipatory nausea and vomiting. A second goal will be to identify prognostic indicators of 1) level of cooperation with treatment, 2) clinically significant reductions in anticipatory side effects. All new pediatric oncology patients will be enlisted to study prevalence rates. At least four to six chemotherapy treatments will encompass a baseline period in which patient and parent ratings of the frequency, duration, and intensity of pre-and postchemotherapy nausea and vomiting, nurse ratings on anticipatory nausea and vomiting, and physiological indices of arousal will be collected. Only those patients who report moderate to severe anticipatory nausea and vomiting over two consecutive rating periods will be enrolled into the treatment portion of the study. Approximately thirty-four children between the ages 7-18 will be randomized equally into one of two groups: Imagery-based relaxation training or biofeedback-enhanced relaxation training. Subjects in both groups will be exposed to these intervention procedures on four occasions over six weeks. They will be followed, using the same assessment measures, after treatment for approximately 4 months to assess the maintenance of treatment effects.